(a) Technical Field
Embodiments of the present invention relate generally to liquid crystal display devices. More particularly, embodiments of the present invention relate to liquid crystal display devices that prevent or reduce color shift.
(b) Description of the Related Art
Liquid crystal display devices are currently one of the most widely used types of flat panel displays. Such devices typically include two display panels on which field generating electrodes such as a pixel electrode and a common electrode are formed, as well as a liquid crystal layer that is disposed therebetween. The devices display an image by applying a voltage to field generating electrodes to generate an electric field in the liquid crystal layer, which determines alignment of liquid crystal molecules of the liquid crystal layer and controls polarization of incident light.
Liquid crystal display devices utilize various modes, and one such mode that has found a degree of acceptance is plane line switching (PLS) mode. In PLS mode, the pixel electrode and the common electrode are formed on the same substrate, and an electric field is formed between the two electrodes to align liquid crystal molecules.
In PLS mode, to improve visibility, one pixel area is divided into two sub-pixel areas, and a direction or orientation of the pixel electrode is different in each sub-pixel area. It is preferable that the area of the pixel electrode is the same in each sub-pixel area.
Also, to reduce load on the data lines while still maintaining transmittance, a passivation layer made of an organic insulating material is formed under the common electrode. The thickness of the organic insulating material is large as compared to inorganic insulating material, meaning that a contact hole formed through the organic insulating material to electrically connect the common electrode to a common line must be relatively large.
The size of this hole means that the contact area between the common electrode and the common line extends at least partially inside the pixel area of one sub-pixel, which reduces the transmittance of that sub-pixel.
This results in the transmittance of one sub-pixel being lower than the transmittances of other sub-pixels. Thus, the transmittances of two sub-pixel areas are different, generating an undesirable a color shift in resulting images.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.